Glossary term · Tests & reports
PET-CT scan (also: PET scan, PET/CT, Positron emission tomography): A PET-CT scan combines a PET scan, which uses a small amount of radioactive tracer, with a CT scan to give detailed images of body tissues.
A PET-CT scan combines a PET scan with a CT scan in one session. The NHS says a PET scan uses a small amount of radiation, given as a tracer injected into a vein, and is commonly used for cancer. Doctors use it to check the size of a cancer and whether it has spread. Oncology teams in India may ask for a recent PET-CT before advising.
How is it done?
The NHS says the tracer is injected about an hour before the scan. The scan usually lasts about half an hour to an hour, lying still while the bed moves through the scanner.
How do I prepare?
- You are usually asked to stop eating 6 hours before, though you can drink water.
- Tell the hospital if fasting is difficult, for example if you have diabetes.
- Bring your medicines list and previous scans.
After the scan
The tracer’s radiation falls to a safe level quickly. The NHS advises limiting prolonged close contact with young children and pregnant people afterwards, for the time staff advise. Plan this if you travel with family.
Why do cancer teams use it?
- To see whether cancer has spread.
- To help plan treatment.
- To investigate symptoms.
- To check response after treatment, where the specialist advises.
Sending a PET-CT
Send the full DICOM study and the report. Include the date and any treatment you had before the scan.
Questions people ask
Should I have a PET-CT at home before travelling?
Ask the reviewing specialist first. Some prefer a recent PET-CT to plan treatment remotely. Others will arrange it in India. Avoid duplicate scans and extra radiation by agreeing the plan before booking anything.
Is a PET-CT the same as a CT with contrast?
No. CT contrast highlights structures such as blood vessels. A PET tracer shows activity in tissues. The two give different information, and a PET-CT includes a CT as part of the same session.
Sources
General information, not medical or legal advice. Rules change: confirm with the official source. Your treating specialist decides on suitability, treatment and length of stay. How we write and check.